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Connexin expression patterns in arrhythmogenic right ventricular cardiomyopathy.
Matthias Paul1, Thomas Wichter, Joachim Gerss
1Division of Cardiology, Department of Cardiovascular Medicine, University Hospital Münster, Münster, Germany. Matthias.Paul@ukmuenster.de
The American Journal of Cardiology
|March 8, 2013
Summary
Arrhythmogenic right ventricular cardiomyopathy (ARVC) involves changes in connexin (Cx) protein expression, particularly Cx40 and Cx45. These alterations in gap junctions may contribute to ventricular arrhythmias in ARVC patients.
Area of Science:
- Cardiology
- Molecular Biology
- Genetics
Background:
- Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited condition causing ventricular tachycardia and sudden death.
- Fibrofatty replacement of the right ventricle is typical, but arrhythmias can occur with minimal replacement, suggesting other mechanisms.
Purpose of the Study:
- To investigate alterations in gap junction protein (connexin [Cx]) expression and distribution in ARVC patients.
- To determine if connexin remodeling contributes to arrhythmogenesis in ARVC.
Main Methods:
- Analyzed messenger RNA (mRNA) expression of Cx40, Cx43, and Cx45 in right ventricular endomyocardial biopsies from 16 ARVC patients and 6 controls.
- Assessed plakophilin-2 mutations in ARVC patients.
Main Results:
- ARVC patients showed significantly reduced mRNA expression of Cx40 and Cx45 compared to controls.
- Cx43 mRNA expression was similar between ARVC patients and controls.
- Plakophilin-2 mutations were found in 25% of patients, with no significant difference in Cx expression between mutation carriers and non-carriers.
Conclusions:
- ARVC is associated with altered connexin expression and distribution at cardiac intercalated discs.
- Changes in gap junction composition, beyond fibrofatty replacement, may promote ventricular arrhythmias in ARVC.
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